This proposal requests funds to assist in the support of the Tenth Biennial Gordon Research Conference on Mammary Gland Biology to be held at Colby-Sawyer College in New London, New Hampshire, June 11th-16th, 1989. This highly successful conference with requests for attendance usually surpassing full capacity, is designed to bring together scientists from a wide spectrum of fields, who share a major interest in the mammary gland. The program is traditionally selected to satisfy the multidisciplinary composition of the audience. The scheduled sessions include: Regulation of Milk-Protein Gene Expression; Structure and Function of Milk Proteins; Growth and Inhibitory Factors in Mammary Development and Function; Intracellular Sorting and Secretory Mechanisms; Protein Hormone Lactogens; Genetics of Breast Cancer; Mucosal Immunity and Growth Hormone Action. The 1987 Conference was highly rated by the Gordon Conference Monitors and was enthusiastically attended by many young inves- tigators. The success of the Conference rests on the unique opportunity for multidisciplinary interaction on an informal basis over a period of one week. The participants know that opinions expressed at the Conference will not be published or cited and therefore they are totally free to explore the impact of their hypotheses on receptive peers. In selecting speakers, special effort was made to invite scientists who had not spoken previously to this group. Of the 31 speakers, 19 are new to the Mammary Gland Biology Gordon Conference program. We request adequate funding to enable the invited speakers to be present at the Conference.